Letterman reacts to McCain’s cancellation.

As part of his plan to suspend his campaign activities, Sen. John McCain (R-AZ) today decided to cancel his appearance on the Late Show with David Letterman. McCain’s campaign reportedly told Letterman that the senator was “racing back to Washington.” That, however, didn’t happen. In his show to air tonight, Letterman shows footage of McCain sitting down with CBS’s Katie Couric for an interview at the same time he was supposed to be on his show. Watch it: